Merck & Moderna's mRNA Cancer Vaccine Shows Promising Results

Breakthroughs in cancer research have been elusive for decades, but scientists are now on the cusp of fulfilling their long-held quest to use vaccines to teach the immune system to spot and destroy cancer cells.

The concept of cancer vaccines has been around for over a century, but it wasn't until recently that mRNA technology finally started showing promise. Merck & Co. and Moderna Inc.'s Phase 3 study combining their personalized mRNA-based vaccine intismeran with the immunotherapy Keytruda is offering the evidence needed to prove that cancer vaccines can work.

The results of the trial, announced via press release on Wednesday, show that adding the vaccine to treatment with Keytruda lengthened the time before people's melanoma returned and the time before tumors appeared in other parts of the body. In a smaller study, the companies reported that intismeran and Keytruda lowered the chances of melanoma returning or metastasizing by 49% compared to Keytruda alone.

While this is a significant breakthrough, there's still much work to be done to show the potential of cancer vaccines extends beyond melanoma and into other types of cancer. Melanoma is considered one of the lower-hanging fruits for immunotherapies because the tumors are littered with mutations, making them easier for the immune system to recognize as different from healthy cells.